I think that what was portrayed in Dream Catcher was meant as a metaphor for the guy's mind, suited to film, rather than an actual memory palace the guy 'built'

I think that what was portrayed in Dream Catcher was meant as a metaphor for the guy's mind, suited to film, rather than an actual memory palace the guy 'built'. The book (as I recall) did not have a memory palace, just dialogue between the guy and this voice in his head. It's been a while, so I might have some of that wrong, but I am sure he did not have a memory palace.